Electric heating unit



Jan. 19, 1937. vw. R. MANSER. 2D

ELECTRIC HEATING UNIT Filed April 27, 1935 CHIC/1:;

16 I 15 INVENTOR.

/ V/L L MIM R. M l/V6276 2/10 ATTORNEY T io Patented Jan. 19, 1937 UNITED STATES PATENT OFFICE 2 Claims.

The invention relates to electric heating units such as are utilized generally in connection with a reflector element for the purpose of projecting radiant heat or infrared waves.

The invention has for an object the provision of a heating unit of the aforesaid nature which will be particularly economical in power consumption in that a maximum amount of the waves is reflected by the associated reflector element.

A further object of the invention resides in the novel construction and arrangement of the re sistor portion of the heating unit, whereby the heat rays emanating therefrom are substantially unobstructed, particularly with respect to the direct forward radiation therefrom.

In carrying out the invention, the insulating refractory upon which the resistor wire is wound is constructed in the form of a helix whose respective convolutions expand outwardly, that is to say, with the base of the conical, or frustoconical element formed, outermost, while the apex or convolution of smallest diameter is located innermost and terminates in a support carrying suitable terminals, which support is adapted also for connection to a reflecting element. Over the core of refractory thus helically constituted, there is wound the resistor wire whose ends are connected to the aforesaid terminals, the convolutions of the resistor winding being transverse to the axis of the wire supporting core. It is preferred, also, to provide a series of ribs on the core which extend longitudinally of the core and are spaced circumferentially thereon to receive the resistor winding.

The nature of the invention, however, will best be understood when described in connection with the accompanying drawing, in which:

Fig. l is a front elevation of the novel heating unit as mounted in a suitable reflector therefor.

Fig. 2 is a side elevation of the unit with the reflector shown in vertical section.

Fig. 3 is an enlarged detail longitudinal section through the heating unit.

Referring to the drawing, l designates a suitable supporting base, standard or bracket for mounting in the desired position a reflector element ll of the usual dished or parabolic form affording a polished reflecting surface I2, the novel heating unit hereinafter described being located substantially in the focus of the said reflector.

The invention relates more especially to the heating unit construction whereby the heat rays emanating therefrom may be projected substantially as a solid cone of heat waves with a max imum surface of direct exposure being presented. To this end, the resistor winding comprising the wire it is not laid on a refractory core in the usual manner, the core as a matter of fact being 5 also of novel construction. As shown, the core 55 in the novel arrangement is in the nature of a helix, the diameter of whose convolutions increases outwardly to provide in effect a cone or frustum of a cone. This core is of suitable electrically insulating and refractory material such as porcelain, lava and the like, in the form of a rod, preferably of circular crosssection, and wound into a helix whose final and outermost convolution lies preferably in a plane at right angles to the axis of the helix.

The wire it constituting the resistor is applied over the core transversely of its longitudinal axis, and, preferably, over a plurality of longitudinal integral ribs H3 which are circumferentialiy spaced thereover. This serves to displace the Winding slightly from the surface of its supporting core reducing conduction and thus accelerating the heating up of the unit, so that the heating efiect is immediately perceptible upon energizing the winding.

The apex or least-diameter portion I! of the convolutions is secured to or is made integral with a suitable support member l8 of material similar to the core l5, and this support serves to carry the said core with its winding of resistance wire i 3. A ferrule i9, moreover, is provided at the opposite end of the member l8, being threaded over its outer surface to fit into a suitable socket Zil of the reflector, and constitutes one terminal of the resistor. The other terminal is constituted by the head 2| of a bolt 22 passing axially through the support member and securely held thereto by the nut 23 at the apex portion I! the other end of the resistor wire being electrically connected to the said nut.

It will be observed that, by constituting the core of the heating unit as a helix in the manner hereinbefore set forth, there will be substantially no interference among the heat waves radiated from the windings over substantially a solid annulus of incandescence, as will be apparent from inspection of Fig. 1 of the drawing. Similarly, the arrangement of the surface exposed toward the reflector is such that there will be no 5 interference among the waves emanating therefrom and directed toward the reflector surface [2 which, in turn, is so shaped as to reflect the waves outwardly to clear substantially the unit. By this expedient, maximum benefit of the developed heat rays is had, and the unit therefore operates at maximum efiiciency.

I claim:

1. An electrical heating unit comprising an insulating and refractory core in the nature of a. rod formed into an outwardly tapering conical spiral, each successive convolution lying substantially Within the next preceding one to admit of projecting without obstruction the developed heat rays from the apex of the spiral outwardly through the same and the outermost convolution lying in a plane, said rod terminating at its inner end in an integral support portion, terminals mounted upon the support, and a resistor wound over the spiral portion of the core and having its respective ends connected with the said terminal.

2. An electrical heating unit comprising an insulating and refractory core in the nature of a rod formed into an outwardly tapering conical spiral, each successive convolution lying substantially within the next preceding one to admit of projecting without obstruction the developed heat rays from the apex of the spiral outwardly through the same, said rod having at its inner end a support portion, a plurality of integral ribs extending longitudinally of the spiral portion of the rod and circumferentially spaced thereon, and a resistor Wound upon said ribs transversely thereto and having its respective ends connected with the said terminal.

WILLIAM R. MANSER, 2n. 

